Porcin follicular fluid has been known to have inhibin like activity on FSH secretion by the pituitary. This inhibin like activity is non steroidal in nature. We will study if the human ovarian follicular fluid also has the inhibin like activity and decreases pituitary secretion of FSH. This will be done by using acutely ovariectomized rats. Efforts will also be made to study the site of action of this non steroidal ovarian inhibin on monolayer cultures of rat anterior pituitary and by slow infusion of follicle fluid into the 3rd ventricle of acutely ovariectomized rats. The data will provide information as to where the ovarian inhibin acts, at the pituitary level or at the higher central nervous system. Studies will also be carried out to observe what ovarian compartment synthesized it. This will be done by culturing various ovarian cell types either singly or in combination and/or by culture of whole ovarian follicle. The effect of various hormones on the synthesis of the ovarian inhibin by the cell types will also be studied.